A patrol plane from the Japanese Maritime Self-Defence Force flies over the disputed islets known as the Senkaku islands in Japan and Diaoyu islands in China, in the East China Sea Photo: Getty

China has reiterated its opposition on Monday to a statement made by the US and Japanese leaders concerning Diaoyu islands and South China Sea.

"We firmly oppose that Japan asked for the endorsement of the United States on its illegal territorial claim in the name of the U.S.-Japan security treaty," said Foreign Ministry spokesperson Geng Shuang said at a daily press briefing on Monday.

Geng’s remark came after Japanese Prime Minister Shinzo Abe got continued backing from US President Donald Trump for its dispute with Beijing over islands in the East China Sea during a meeting over the weekend.

The statement after the weekend meeting said the two leaders affirmed that Article 5 of the U.S.-Japan security treaty covered the islands, known as the Senkaku in Japan and the Diaoyu in China.

Geng said China was "seriously concerned and resolutely opposed", adding that the islands had been China's inherent territory since ancient times.

"No matter what anyone says or does, it cannot change the fact that the Diaoyu Islands belong to China, and cannot shake China's resolve and determination to protect national sovereignty and territory," he said.

He also said that Japan and the United States should speak and act discreetly and stop making false statements so as to avoid complicating relevant issues and casting a shadow on regional peace and stability.

The joint U.S.-Japan statement also mentioned China's reef construction in the South China Sea. Geng said that China's construction on its own islands was "totally within China's sovereignty and has nothing to do with militarization." And the leading cause of militarization in the South China Sea was that some countries had sent aircraft and vessels to show military force or drive a wedge between countries in the region, he said.

Geng also urged the US and Japan to “view the South China Sea issue objectively and rationally and do more to contribute to the peace and stability of the South China Sea.”

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